Trouble using "apt-get update"

Question

I am trying to use the command "apt-get update", but it gives me this error. It's not the only command that gives errors like these.

    apt-get update
E: Could not open lock file /var/lib/apt/lists/lock - open (13: Permission denied)
E: Unable to lock directory /var/lib/apt/lists/
E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied)
E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?

How can I fix that?

Answer 1

You need to run the command as root:

sudo apt-get update
sudo apt-get upgrade